A host device may include an imaging unit configured to capture an image of a guest device, and a communication unit configured to communicate with the guest device. The host device may include circuitry configured to identify, in the image of the guest device, identification information corresponding to the guest device, the identification information being displayed on a screen included on the guest device. The circuitry may calculate, based on the identification of the identification information in the image, an arrangement position of the guest device. The circuitry may assign, based on the calculated arrangement position, assigned data to the guest device. The circuitry may transmit one or more of the calculated arrangement position and information associated with the assigned data to the guest device.